There’s a lot wrong with your model. I’m not sure how you went about creating it all but you have a lot of internal faces and places where there need to be intersections. Sit back for a few minutes and let me work on it.

To be honest, I’m not sure where you went wrong but it looks like there were several places. Copy and Paste works fine. I used copy quite a bit to draw my version of it. As you can see in the screen shot, there are no internal faces and no holes.

It might be an order of operations thing but you could also stand to work at a larger size. In your case I would suggest setting units to meters and treat them as if they were millimeters. Instead of doing that, I worked at the same size as your original so I could copy the bull’s face and other details over. I used the Dave Method when it came time to create intersections and clean things up.Maverick v4.skp (1.8 MB)

Did you try drawing the entire thing flat and then extrude faces upward to make the relief?

3am thoughts… I realized why I had so many internal faces. I drew the bull and rope separate from the plate in 2d (not a problem). Where I messed up was I extruded the 2d shape and then copy and pasted it onto the plate. Next time I’ll stick with 2d until I’m ready to extrude everything, should make deleting overlapping lines much easier too!

One of the problems that people create for themselves is trying to draw everything out flat before going 3D. You might find it easiest if you start with a large rectangle and extrude it up to the thickness of the base disk. The draw everything on it and start extruding from there. You shouldn’t wind up with any internal faces, then.